MODESTO, California (CNN) --News cameras will not be allowed in the courtroom for a September 9 preliminary hearing of a California man accused of killing his pregnant wife, a California judge ruled Monday.

The decision by Superior Court Judge Al Girolami followed a decision he made last week to keep the September hearing for Scott Peterson open to the public.

Scott Peterson, 30, has pleaded innocent in the killings of his pregnant wife, Laci Peterson, 27, who vanished on Christmas Eve, and their unborn son. The bodies washed ashore in April along the San Francisco Bay.

Girolami's ruling about cameras followed after arguments by media, prosecutors and defense attorneys on the issue. Preliminary hearings are typically used by a judge to determine if prosecutors have enough evidence against a defendant to justify a trial.

Several broadcast outlets, including CNN, Court TV and the networks, had argued that a camera should be allowed.

In a seven-page ruling responding to nearly 1,000 pages of arguments on the issue, Girolami cited 18 criteria that he said were "most critical" to the decision.

"Particularly compelling," the judge wrote, was "that the victims' family has requested that the preliminary hearing not be filmed."

"While the media cite a 'community therapeutic value' in favor of coverage, the court believes that whatever therapeutic value there may be in the evidence of this case becoming public is sufficiently served by it being available to members of the public via other modes, such as the print media and the Internet," Girolami wrote.

Girolami also wrote that the "nature of the case" argued against cameras, as did the privacy rights of all participants and the effect cameras could have on seating a "fair and unbiased jury."

Scott Peterson's attorneys filed a court document last week against the media petition, saying a camera would prohibit Peterson from having a fair trial. The defense had pointed out that a standing gag order, which pertains to all statements by witnesses and counsel, was issued to protect the ability of both sides to select a fair and impartial jury.

In addition, if the hearing were to be open to the media, "the mere introduction of evidence at the preliminary hearing" could put the party introducing that evidence in violation of the gag order, the defense said.

The Stanislaus County district attorney had requested that Girolami bar cameras from the preliminary hearing out of respect for Laci Peterson's family.

Television media attorneys countered that neither the prosecution nor defense argument offered sufficient reason to prohibit cameras. They said that when the family, the police and Scott Peterson himself asked for national publicity to help find Laci Peterson, they received it.

The media attorneys also offered federal and state studies purportedly showing that cameras in courtrooms had little or no influence on the conduct of trials.

The Peterson case has received extensive publicity, prompting the parents of Laci Peterson last week to send a letter via fax to news media, begging them to omit "unnecessary graphic details" when reporting on the deaths.

Girolami's ruling on cameras followed a number of other decisions he made last week:

• Girolami responded to a prosecution motion to survey registered voters in Stanislaus and two other counties about how familiar they are with the case. The prosecution hopes to use the responses to fight any defense request for a change of venue. The judge said that before he makes a decision he wants to see a copy of the questionnaire.

• Girolami ordered that information from wiretaps on Scott Peterson remain sealed until a decision is made on whether to admit it as evidence.

• Girolami asked the district attorney to investigate whether defense attorneys violated a court gag order based on an article in the Modesto Bee.